1. Field of the Invention
This invention relates to a cassette loading device for a recording and/or reproducing apparatus of the kind to be loaded with a cassette which houses therein a record bearing medium and is provided with at least a window for exposing a portion of the medium and a movable cover for the window.
2. Description of the Prior Art
In a recording and/or reproducing apparatus adapted for recording and/or reproducing a signal in or from recording tracks concentrically or helically formed on a disc shaped record bearing medium such as a flexible magnetic disc, it is necessary to provide a device arranged to have a cassette which houses the disc shaped record bearing medium inserted from the outside of the apparatus and to place the cassette at a position for recording and/or reproduction within the apparatus.
In some cases on both sides of the cassette are formed windows, one arranged to allow a magnetic head to confront the recording surface of the magnetic disc and another to have a stabilizer plate come in for stabilizing the disc near the head. If the cassette which has these windows is left unused over a long period of time, large particles of dust enter the cassette and electrostatically stick to the surface of the magnetic disc. If the recording and/or reproducing apparatus is loaded with such a disc to perform recording and/or reproduction, the dust will stick and the magnetic head to degrade the recording and reproducing performance of the apparatus or damage the surfaces of the magnetic discs. In addition to this, the disc surface exposed to the outside through the window is likely to be damaged by external things when they come in contact with the disc.
To solve these problems, there has been proposed an arrangement wherein the cassette is provided with a shutter for movably covering the stabilizer plate inserting window and the magnetic head inserting window therewith; while, on the side of the apparatus, a shutter operating member is provided at a part of a movable cassette holder which is arranged to hold the cassette when the cassette is loaded on the apparatus at a predetermined position. In inserting or taking out the cassette, the shutter can be opened or closed by means of this shutter operating member.
In loading the cassette which is provided with the shutter into a predetermined position by inserting the cassette into the cassette holder, the cassette holder is lowered after the insertion and then must be correctly positioned by pressing it against a positioning member which is provided on the chassis of the recording and/or reproducing apparatus. For correct positioning, the cassette holder is further lowered to a slight extent relative to the cassette which has already come to a stop. In other words, the cassette holder is arranged to perform an action called an over stroke. At the time of this over-stroke action, if the shutter operating member is lowered while engaged with the shutter attached to the cassette, an exessive force would be exerted thereon. Then, either the shutter operating member might be damaged or the shutter might be damaged in part. Further, in such a case, the cassette might be loaded in a tilted state to prevent satisfactory performance of recording or reproduction.